1. Field of the Invention
The present invention relates to a camera removably connected to an external connecting device such as a personal computer, a personal digital assistant (PDA: information terminal equipment) or a word processor, to a connecting device for use with a camera, and to such a camera system including such a camera and connecting device.
2. Related Background Art
A digital camera for digital recording is known such as shown in FIG. 7. In FIG. 7, reference numeral 710 represents a card-type digital camera, and reference numeral 720 represents a general personal computer (hereinafter called a PC). The internal structures thereof are shown in block in FIG. 7.
In the structures shown in FIG. 7, a subject image passed through a lens 701 of an optical system is picked up by an image pickup element CCD 711, subjected to predetermined processes such as CDS and AGC, and amplified to a predetermined level by a pre-amplifier 713. The analog image signal is then converted into a digital image signal by an A/D converter 714, processed by a signal processing circuit 715, and temporarily stored in a memory 716.
The above-described operations are controlled by a controller 717 which also outputs an interrupt signal to a PC 720. Upon reception of this interrupt signal, PC 720 performs an interrupt routine.
PC 720 is generally constituted of a CPU 721, a main memory 722, a display 723, a mouse 724, a keyboard 725, an HDD 726, an FDD 727 and a local bus 728.
In such a conventional card-type digital camera system, the interrupt routine of PC 720 copies an image in the memory 716 into the main memory 722 under the control of CPU 721 of PC 720. This copied image is displayed on the display 723 by an application program. If these operations are performed successively, a moving image can be displayed. If a space key of the keyboard is depressed during the display of a moving image, a still image can be saved in a clip board or in a disk medium such as a hard disk.
With such a conventional camera system of the type that a camera head unit and a camera card are interconnected by a cable, a still image can be picked up only by actuating a keyboard or mouse of the PC.
The present invention has been made in order to solve the above problem and provides a camera capable of picking up a still image by actuating a release switch of the camera, a connecting device for such a camera and a camera system thereof.
According to one aspect of the present invention, a camera is configured as follows:
(1) A camera is removably connected to an external connecting device such that the function of a release switch of the camera can be changed by the connecting device connected to the camera.
(2) The camera described in (1), wherein the release switch performs a desired function, in accordance with selecting means in application software.
(3) The camera described in (1), wherein a medium stores the status of the release switch, and the status stored in the medium is changed as desired by selecting means provided in application software.
(4) The camera described in (3), wherein the medium is a disk.
(5) The camera described in (3), wherein the medium is a shared memory.
(6) The camera described in (1), wherein an interrupt signal is sent to the connecting device upon actuation of the release button, and in response to the interrupt signal the connecting device processes an image signal picked up by the camera.
According to another aspect of the present invention, a camera connecting device is configured as follows:
(7) A connecting device is removably connected to a camera, and includes input means having the same function as a release switch of the camera.
(8) A connecting device is removably connected to a camera, and includes means for detecting whether the camera is equipped with a release switch.
According to still another aspect of the present invention, a camera system is configured as follows:
(9) A camera system includes a camera and a connecting device removably connected to the camera, the system includes means for detecting whether a camera with a release switch or a camera without a release switch is connected in the system.
(10) The system described in (9) wherein, the system is adapted to start up a photographing operation by the release switch of the camera, when the camera having the release switch is connected.
(11) The system described in (9), wherein a display of the detecting means is changed in accordance with a detection to whether a camera with a release switch or a camera without a release switch is connected in the system.